1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  fs/partitions/mac.c
4 *
5 *  Code extracted from drivers/block/genhd.c
6 *  Copyright (C) 1991-1998  Linus Torvalds
7 *  Re-organised Feb 1998 Russell King
8 */
9
10#include <linux/ctype.h>
11#include "check.h"
12#include "mac.h"
13
14#ifdef CONFIG_PPC_PMAC
15#include <asm/machdep.h>
16extern void note_bootable_part(dev_t dev, int part, int goodness);
17#endif
18
19/*
20 * Code to understand MacOS partition tables.
21 */
22
23#ifdef CONFIG_PPC_PMAC
24static inline void mac_fix_string(char *stg, int len)
25{
26	int i;
27
28	for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
29		stg[i] = 0;
30}
31#endif
32
33int mac_partition(struct parsed_partitions *state)
34{
35	Sector sect;
36	unsigned char *data;
37	int slot, blocks_in_map;
38	unsigned secsize, datasize, partoffset;
39#ifdef CONFIG_PPC_PMAC
40	int found_root = 0;
41	int found_root_goodness = 0;
42#endif
43	struct mac_partition *part;
44	struct mac_driver_desc *md;
45
46	/* Get 0th block and look at the first partition map entry. */
47	md = read_part_sector(state, 0, &sect);
48	if (!md)
49		return -1;
50	if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
51		put_dev_sector(sect);
52		return 0;
53	}
54	secsize = be16_to_cpu(md->block_size);
55	put_dev_sector(sect);
56	datasize = round_down(secsize, 512);
57	data = read_part_sector(state, datasize / 512, &sect);
58	if (!data)
59		return -1;
60	partoffset = secsize % 512;
61	if (partoffset + sizeof(*part) > datasize)
62		return -1;
63	part = (struct mac_partition *) (data + partoffset);
64	if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
65		put_dev_sector(sect);
66		return 0;		/* not a MacOS disk */
67	}
68	blocks_in_map = be32_to_cpu(part->map_count);
69	if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
70		put_dev_sector(sect);
71		return 0;
72	}
73
74	if (blocks_in_map >= state->limit)
75		blocks_in_map = state->limit - 1;
76
77	strlcat(state->pp_buf, " [mac]", PAGE_SIZE);
78	for (slot = 1; slot <= blocks_in_map; ++slot) {
79		int pos = slot * secsize;
80		put_dev_sector(sect);
81		data = read_part_sector(state, pos/512, &sect);
82		if (!data)
83			return -1;
84		part = (struct mac_partition *) (data + pos%512);
85		if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
86			break;
87		put_partition(state, slot,
88			be32_to_cpu(part->start_block) * (secsize/512),
89			be32_to_cpu(part->block_count) * (secsize/512));
90
91		if (!strncasecmp(part->type, "Linux_RAID", 10))
92			state->parts[slot].flags = ADDPART_FLAG_RAID;
93#ifdef CONFIG_PPC_PMAC
94		/*
95		 * If this is the first bootable partition, tell the
96		 * setup code, in case it wants to make this the root.
97		 */
98		if (machine_is(powermac)) {
99			int goodness = 0;
100
101			mac_fix_string(part->processor, 16);
102			mac_fix_string(part->name, 32);
103			mac_fix_string(part->type, 32);
104
105			if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
106			    && strcasecmp(part->processor, "powerpc") == 0)
107				goodness++;
108
109			if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
110			    || (strncasecmp(part->type, "Linux", 5) == 0
111			        && strcasecmp(part->type, "Linux_swap") != 0)) {
112				int i, l;
113
114				goodness++;
115				l = strlen(part->name);
116				if (strcmp(part->name, "/") == 0)
117					goodness++;
118				for (i = 0; i <= l - 4; ++i) {
119					if (strncasecmp(part->name + i, "root",
120						     4) == 0) {
121						goodness += 2;
122						break;
123					}
124				}
125				if (strncasecmp(part->name, "swap", 4) == 0)
126					goodness--;
127			}
128
129			if (goodness > found_root_goodness) {
130				found_root = slot;
131				found_root_goodness = goodness;
132			}
133		}
134#endif /* CONFIG_PPC_PMAC */
135	}
136#ifdef CONFIG_PPC_PMAC
137	if (found_root_goodness)
138		note_bootable_part(state->disk->part0->bd_dev, found_root,
139				   found_root_goodness);
140#endif
141
142	put_dev_sector(sect);
143	strlcat(state->pp_buf, "\n", PAGE_SIZE);
144	return 1;
145}
146